Art of coloring and marking materials



Patented May 24, 1938 PATENT o1=1=1cE 2,118,431 ART OF COLORING ANDMARKING MATE- RIALS Albert E. Gessler, Ardsiey-on-Hudson, N. Y.,assignor to Interchemical Corporation, a corporation of Ohio No Drawing.Application January 14, 1935, Serial No. 1,605

9 Claims.

This invention relates to improvements in the art of coloring andmarking materials. vides a new method for coloring, partially coloringand marking materials of many different sorts, and a new composition ofmatter which I I term. a coloring medium and which may be used for manyof the purposes for which printing inks, paints, lacquers, stains anddyes have heretofore been used. No claim is made in the present ap- 10plication to the coloring medium, since this is claimed in my co-pendingapplication Serial No. 163,243, filed September 10, 1937. The inventioneffects improvement in the coloring art both in the quality of theproduct and in economy of procedure.

' The new composition of coloring medium which I have invented has theproperty of precipitating a water-insoluble pigment when water isapplied to it. In coloring or marking materials, the new coloring mediumis first applied to the material and thereafter water is applied to thecoloring medium on the material. This causes a precipitation of a finelydivided, water-insoluble pigment on the surface and in the pores andfibres of the material, producing a brilliant water fast color.

The new coloring medium has been produced by dissolving pigment-formingreagents in an organic solvent which is miscible with water. The

pigment-forming reagents are adapted to enter intoa reaction producing apractically waterinsoluble pigment. For most purposes, a thickener isalso dissolved in the solution to facilitate the application of thecoloring medium and to prevent it from spreading on the material towhich it is applied.

The organic solvent used in the composition is miscible with water. Itis in many cases desirable that it should be of low volatility in orderthat the composition may not dry upon the printing press or brush orother means by which it may be applied. Diethylene-glycol-ethyl-etherand diethylene-glycol-butyl-ether are examples of organic solventshaving these characteristics. The solvent is free from water, orpractically so.

The pigment-forming reagents are soluble in the organic solvent. Theymay consist of dye and a precipitant therefor, both of which are solublein the organic solvent, and which are in condition to react with eachother. The so-called basic dyes are particularly desirable in mycoloring medium because they are very brilliant, powerful and ofier awide range of hues. Other types of dyes may, however, be used. Asprecipitants It propores and fibres of the material.

acid, phospho-molybdic acid and similar acids. most desirable, but othersuitable precipitants for the basic dyes may be used. It will beunderstood that in case the dyes used are not basic dyes. it isnecessary to select their specific precipitants for them. Instead ofusing a dye and a precipitant therefor, other pigment-forming reagentsmay be used, such as the intermediates for insoluble azo colors or vatdyes or the like.

The amount of pigment-forming reagents which must be used maybe verysmall. A basic dye amounting to only one-half of one per cent. of theamount of solvent has given excellent results. This appears to bebecause of the high coloring power of the very fine particle size'of thepigment precipitated on the surface or in the pores of the material.

The,thickener, if used in the composition, may be a colloid capable ofbeing dissolved or dispersed in the organic solvent and of beingeliminated or coagulated by adding water. It may consist of awater-insoluble colloid which is precipitated when water is applied, orit may. be a watersoluble colloid which can be washed away when water isapplied. I have found nitrocellulose most desirable as a water-insolublethickener. Methyl cellulose may be used as a water-soluble thickener.Functions of the thickener are to give the composition a consistencyconvenient for ap-' plication, to prevent spreading of the compositionin the material to be colored, and also in many cases to bind thepigment to surfaces. The use of the thickener does not necessarilyprevent the penetration of the coloring medium into the Whether athickener should be used and the amount of the thickener, therefore,depend on the nature'of the material to be colored and the way in whichthe coloring medium is applied to it.

To make the nature of my invention still more clear, I will now givespecific illustrative examples of coloring media and coloring methodsembodying it:

Example 1 Parts Dye: Rhodamlne 6G (Schultz No.

571) 10 Precipitant: Duo deci phospho-tungstic acid 25 Thickener:Nitrocellulose (1000 seconds viscosity) Solvent: Moisture-freediethylene-glycol-ethyl-ether 1000 This composition is a viscous liquid.It is desirable especially for application to fabrics, but may be usedfor other materials.

To produce a colored design in a fabric, the composition is applied tothe fabric or to limited areas of the fabric by printing, stencilling,brushing, hand painting or the like. The composition is liquid enough topenetrate into the fibres of the fabric but is thickened sumciently toprevent it from spreading. After the composition has been applied in anyone of these ways, the fabric is immersed in water or otherwise wettedwith water. This results in the precipitation of a fine pigment on thesurface and in the fibres of the fabric, with the effect that the coloris fast to water and washing. Besides precipitating the pigment in thefibres, the water has the effect of washing away most or all of theorganic solvent and any by-products of the precipitation reaction. Thethickener is precipitated in the fibres in an impalpable form so thatits presence cannot, practically, be detected by the touch. If awater-soluble thickener is substituted for the insoluble thickener inthe example given, the effect is the same except that most or all ofthis thickener is washed away by the water.

It is possible at the same time to apply the coloring medium without, orwith less of, the

thickening colloid to the entire material surface,

or to large areas of the same, by printing, stencilling, hand brushing,and particularly by spraying, and thereafter wetting with water-by asuitable method. This permits of using the coloring material in morefluid form, where such is desirable for certain methods of applicationand certain types of materials to be colored. Although without thethickening colloid there will be a tendency for the spreading of thesolution on the surface, still the material or the method of applicationmay be such that this will be minimized and controlled, or the designfor decoration may make this spreading immaterial or even desirable.

' Example 2 l Parts Dye: Rhodamine 6G (Schultz No. 571) 3 Precipitant:Duo deci phospho-tungstic acid- 9 Thickener: Nitrocellulose second) 30Solvent: 1 diethylene glycol ethylether 45 3 diethylene glycolbutylether This composition has substantially the consistency ofprinting ink. It is desirable in printing on paper and many othermaterials in many different wa'ys.

After application of the composition to the material by printing, wateris brought into contact with the printed material. This immediatelycauses the precipitation of a finely divided pigment on the surface andin the surface pores of the material. This effects practicallyinstantaneous drying or setting of the ink by precipitating the pigmentin such finely divided form on surface and in their pores of thematerial that it clings to them very tenaciously. The moisture also hasthe effect of precipitating the nitrocellulose, which also serves tobind the pigment to the surface of the sheet, with the effect offastening the pigment still more securely to the surface and efiectivelypreventing smudging, rubbing or offsetting. Subsequent rolling, piling,and otherwise handling the printed material is rendered,

as a result, more immediate and easier.

on even slightly porous surfaces such as that of ordinary paper, thefinely precipitated pigquently in printing on such surfaces, a thickenerhaving no binding power may be substituted for nitrocellulose in thecomposition given.

The particles of pigment precipitated are so fine and uniform that greatbrilliance, lustre, uniformity of coloring, and economy in the amount ofpigment used result.

Only a very small amount of water is necessary to. precipitate thepigment and colloid. The forming of the pigment and the setting of theink may, therefore, be effected by mere dampening of the printingmatter, which in no way injures the paper or other material on which thecoloring medium has been printed.

A further feature of the invention which is useful when the coloringmedium is made of ordinary commercial, and therefore not chemicallypure, materials consists in introducing a neutralizing agent tocounteract the effect of possible acidity or alkalinity introduced byimpurities in the pigment-forming reagents, which might otherwise havean injurious effect. Thus, in the particular compositions abovespecified, the precipitant, phospho-tungstic acid, may contain as animpurity some. mineral acid or other strong acid which, in time, woulddeleteriously affect the dye. In accordance with my invention, thisdanger may be eliminated by introducing a weak alkali, such asdiphenylamine or sodium acetate, which has a tendency to neutralizeexcess mineral acid or strong acid which may be present, but does notreact with or impair the effectiveness of the phospho-tungstic acidprecipitant.

My invention is not limited to the particular reagents which have beenspecified in theillustrative formulae, but includes all substances whichare equivalent to them for the particular functions and purposesspecified. Furthermore, the invention is not limited to .the particularproportions stated'in the specific examples, as they may be variedconsiderably without substantially changing the function and operationof the solution. Thus even if, by an increase'in the proportion ofpigment-forming reagents or by the presence of some water in thesolution, a substantial amount of pigment or other material isprecipitated so as to be visible or settle out in the solution before itis applied to the material to be colored, the further pigment which isso precipitated after the solution is applied and the material is wettedfunctions in the manner which has been de-- scribed.

The word solution, as used throughout the foregoing specification and inthe claims which follow, is used in its common sense.to includecolloidal dispersions.

The word coloring, as used in this specification and the claims whichfollow, is used in a generic sense to include changing the appearance ofall or a part of the surface of the material and includes marking inblack or white as well as in other colors.

What I claim is: V

1. The process of coloring materials, whic comprises applying to thematerial to be colored a water-miscible solution having the property ofprecipitating a water-insoluble pigment on the application of water, andthen moistening the material with water to precipitate pigment onpregnating the fibres and pores of the material with a water-misciblesolution having the property of precipitating a water-insoluble pigmenton the application of water, and thenwetting the material with water toprecipitate pigment on the surface of and in the fibres and pores of thematerial. r

3. The process of decorating materials, which comprises coating thesurface of and impregnating the fibres and pores of a definitely limitedarea. of the material with a thickened watermiscible solutionfrom whicha water-insoluble pigment may be precipitated by the application ofwater, and wetting the treated material with water to precipitate thepigment on the surface of and in the fibres of said area of thematerial.

4. The process of printing, which comprises applying to the surface of amaterial an ink containing a solution having the property ofprecipitating a water-insoluble pigment on the application of water, andthen moistening said ink on the material.

5. The process of printing, which comprises applying to the. surface ofa material an ink containing a solution having the property ofprecipitating a water-insoluble pigment and a binder on the applicationof water, and then mois= tening said ink on the material.

6. The process of printing, which comprises applying to the surface of amaterial an ink containing a solution having the property ofprecipitating a water-insoluble pigment on the application of water, andthen dampening the material.

'7. The process of coloring materials, which comprises dissolvingpigment-forming reagents in a water-miscible organic solvent in whichthey are both soluble, applying the solution to the material to becolored, and applying water to the solution on the material to causeprecipitation of pigment on the material.

8. The process of coloring materials, which comprises dissolvingpigment-forming reagents in a water-miscible organic solvent in whichthey are both soluble, thickening; said solution with a colloiddispersible in said solvent and precipitable therefrom by water,applying the thickened solution to the material to be colored, andapplying water to the solution on the material to cause precipitation ofpigment and-colloid on the material.

9. The process of coloring materials, which comprises dissolvingpigment-forming reagents in a water-miscible organic solvent in whichthey are both soluble, thickening said solution in a colloid dispersiblein said solvent and soluble in water, applying said thickened solutionto the material to be colored, and applying water to the material tocause precipitation of pigment on the material and to wash away thecolloid.

ALBERT E. GESSLER.

